def centerOfMass(img, yx, window=5):
"""
find peak by center of mass in a 2D image
img: a 2D image array
yx: (y,x) in the image
window: a window where CM calculation is performed on
return yx
"""
# prepare small image
s = N.array([window, window])
c = s / 2.
yx = N.round_(yx)
yx -= c
yi, xi = N.indices(s)
yi += yx[0]
xi += yx[1]
cc = img[yi, xi]
# calculate center of mass
yxi = N.indices(s)
yxi *= cc
yxi = yxi.T
vv = N.sum(yxi, axis=0)
vv = N.sum(vv, axis=0)
yxs = vv / float(N.sum(cc))
yxs += yx
return yxs
def gaussianArr2D(
shape=(256, 256), sigma=[2., 2.], peakVal=None, orig=None, rot=0):
"""
>1.5x faster implemetation than gaussianArrND
shape: (y,x)
sigma: scaler or [sigmay, sigmax]
orig: (y,x)
rot: scaler anti-clockwise
return N.float32
"""
shape = N.asarray(shape, N.uint)
try:
if len(sigma) == len(shape):
sy = 2 * (sigma[0] * sigma[0])
sx = 2 * (sigma[1] * sigma[1])
elif len(sigma) == 1:
sx = sy = 2 * (sigma[0] * sigma[0])
else:
raise ValueError, 'sigma must be scaler or [sigmay, sigmax]'
except TypeError: # sigma scaler
sx = sy = 2 * (sigma * sigma)
# print y, x
if rot:
yyi, xxi = imgFit.rotateIndices2D(shape, rot, orig, N.float32)
else:
if orig is None:
y, x = shape / 2. - 0.5 # pixel center remove
else:
y, x = N.subtract(orig, 0.5) # pixel center remove
yi, xi = N.indices(shape, dtype=N.float32)
yyi = y - yi
xxi = x - xi
k1 = -(yyi) * (yyi) / (sy) - (xxi) * (xxi) / (sx)
if peakVal:
k0 = peakVal
else:
k0 = 1. / ((sx + sy) / 2. * ((2 * N.pi)**0.5))
return k0 * N.exp(k1)
def radialaverage(data, center=None, useMaxShape=False):
"""
data: ND array
center: coordinate of center of radii
useMinShape: the output uses the maximum shape available
return 1D array
"""
if center is None:
center = N.array(data.shape) // 2
if len(center) != data.ndim:
raise ValueError, 'dimension of center (%i) does not match the dimension of data (%i)' % (
len(center), data.ndim)
zyx = N.indices((data.shape))
r = N.zeros(data.shape, N.float32)
for i, t in enumerate(zyx):
r += (t - center[i])**2
r = N.sqrt(r)
#y, x = N.indices((data.shape))
#r = N.sqrt((x - center[0])**2 + (y - center[1])**2) # distance from the center
r = r.astype(N.int)
if data.dtype.type in (N.complex64, N.complex128):
rbin = N.bincount(r.ravel(), data.real.ravel())
ibin = N.bincount(r.ravel(), data.imag.ravel())
tbin = N.empty(rbin.shape, data.dtype.type)
tbin.real = rbin
tbin.imag = ibin
else:
tbin = N.bincount(r.ravel(), data.ravel())
nr = N.bincount(r.ravel())
radialprofile = tbin / nr.astype(N.float32)
if not useMaxShape:
minShape = min(list(N.array(data.shape) - center) + list(center))
radialprofile = radialprofile[:minShape]
return radialprofile
def getSphericalAbbe(arr3D, kmin=2, kmax=60, plot=False):
"""
compare frequency above and below the focus
return amplitude var(above)/var(below)
"""
afz = getFourierZprofile(arr3D)
# get z profile around the reasonable frequency
aa = N.abs(N.average(afz[:, kmin:kmax], axis=1))
# previously it was N.average(N.abs(afz[:,kmin:kmax]), axis=1), but that seems wrong...
# findMax
inds = N.indices(aa.shape, dtype=N.float64)
v, _0, _1, z = U.findMax(aa)
parm, check = imgFit.fitGaussianND(aa, [z], window=len(aa))
if check == 5:
raise RuntimeError, 'Peak not found check=%i' % check
gg = imgFit.yGaussianND(parm, inds, 3)
amg = aa - gg
z0 = parm[2]
mask = (parm[-1] * 3) / 2. # sigma * 3 / 2
ms0 = N.ceil(z0 - mask)
ms1 = N.ceil(z0 + mask)
amg[ms0:ms1] = 0
below = N.var(amg[:ms0])
above = N.var(amg[ms1:])
if plot:
Y.ploty(N.array((aa, gg, amg)))
print 'below: ', below
print 'above: ', above
print ms0, ms1, z0
return above / (above + below) #above / below
def Xcorr(a,
b,
highpassSigma=2.5,
wiener=0.2,
cutoffFreq=3,
forceSecondPeak=None,
acceptOrigin=True,
maskSigmaFact=1.,
removeY=None,
removeX=None,
ret=None,
normalize=True,
gFit=True,
lap=None,
win=11):
"""
returns (y,x), image
if ret is True, returns [v, yx, image]
to get yx cordinate of the image,
yx += N.divide(picture.shape, 2)
a, b: 2D array
highpassSigma: sigma value used for highpass pre-filter
wiener: wiener value used for highpass pre-filter
cutoffFreq: kill lowest frequency component from 0 to this level
forceSecondPeak: If input is n>0 (True is 1), pick up n-th peak
acceptOrigin: If None, result at origin is rejected, look for the next peak
maskSigmaFact: Modifier to remove previous peak to look for another peak
removeYX: Rremove given number of pixel high intensity lines of the Xcorr
Y: Vertical, X: Horizontal
normalize: intensity normalized
gFit: peak is fitted to 2D gaussian array, if None use center of mass
win: window for gFit
if b is a + (y,x) then, answer is (-y,-x)
"""
shapeA = N.asarray(a.shape)
shapeB = N.asarray(b.shape)
shapeM = N.max([shapeA, shapeB], axis=0)
shapeM = N.where(shapeM % 2, shapeM + 1, shapeM)
center = shapeM / 2.
arrs = [a, b]
arrsS = ['a', 'b']
arrsF = []
for i, arr in enumerate(arrs):
if arr.dtype not in [N.float32, N.float64]:
arr = N.asarray(arr, N.float32)
# this convolution has to be done beforehand to remove 2 pixels at the edge
if lap == 'nothing':
pass
elif lap:
arr = arr_Laplace(arr, mask=2)
else:
arr = arr_sorbel(arr, mask=1)
if N.sometrue(shapeA < shapeM):
arr = paddingMed(arr, shapeM)
if normalize:
mi, ma, me, sd = U.mmms(arr)
arr = (arr - me) / sd
if i == 1:
arr = F.shift(arr)
af = F.rfft(arr)
af = highPassF(af, highpassSigma, wiener, cutoffFreq)
arrsF.append(af)
# start cross correlation
af, bf = arrsF
bf = bf.conjugate()
cf = af * bf
# go back to space domain
c = F.irfft(cf)
# c = _changeOrigin(cr)
# removing lines
if removeX:
yi, xi = N.indices((removeX, shapeM[-1])) #sx))
yi += center[-2] - removeX / 2. #sy/2 - removeX/2
c[yi, xi] = 0
if removeY:
yi, xi = N.indices((shapeM[-2], removeY)) #sy, removeY))
xi += center[-1] - removeY / 2. #sx/2 - removeY/2
c[yi, xi] = 0
# find the first peak
if gFit:
v, yx, s = findMaxWithGFit(c, win=win) #, window=win, gFit=gFit)
if v == 0:
v, yx, s = findMaxWithGFit(c, win=win +
2) #, window=win+2, gFit=gFit)
if v == 0:
v = U.findMax(c)[0]
yx = N.add(yx, 0.5)
#yx += 0.5
else:
vzyx = U.findMax(c)
v = vzyx[0]
yx = vzyx[-2:]
s = 2.5
yx -= center
if N.alltrue(N.abs(yx) < 1.0) and not acceptOrigin:
forceSecondPeak = True
# forceSecondPeak:
if not forceSecondPeak:
forceSecondPeak = 0
for i in range(int(forceSecondPeak)):
print '%i peak was removed' % (i + 1) #, sigma: %.2f' % (i+1, s)
yx += center
g = gaussianArr2D(c.shape, sigma=s / maskSigmaFact, peakVal=v, orig=yx)
c = c - g
#c = mask_gaussian(c, yx[0], yx[1], v, s)
if gFit:
v, yx, s = findMaxWithGFit(c, win=win) #, window=win, gFit=gFit)
if v == 0:
v, yx, s = findMaxWithGFit(c, win=win +
2) #, window=win+2, gFit=gFit)
if v == 0:
v = U.findMax(c)[0]
yx -= (center - 0.5)
else:
vzyx = U.findMax(c)
v = vzyx[0]
if not gFit:
yx = centerOfMass(c, vzyx[-2:]) - center
if lap is not 'nothing':
c = paddingValue(c, shapeM + 2)
if ret == 2:
return yx, af, bf.conjugate()
elif ret:
return v, yx, c
else:
return yx, c